Definition of Hepatitis A immunization

Hepatitis A immunization: A vaccine that may be considered for individuals in high-risk settings for contracting the hepatitis A virus. Two hepatitis A vaccines (brand names: Havrix and Vaqta) are commercially available in the US. Both are highly effective and provide protection even after one dose. Two doses are recommended for adults, and three doses are recommended for children under 18 years of age to provide prolonged protection.